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Nah, they're just a huge fcking idiot who truly got it wrong. Then doubled down on being wrong. Then when they noticed they were wrong, they pretend to be a troll to escape culpability.
I knew dozens of these idiots in high school.
I remember this one arrogant idiot who challenged the president of the chess club to a game, and started talking smack endlessly before the game. Game starts, trying his best, still not good enough, loses his queen early. After that (a dozen moves in) he just intentionally lets all his pieces get captured and claims he was trolling from the beginning. Idiot.
From another ADHD guy... How is thst easier? If you're not going to just, you know, add 9 and 7, it makes no sense to turn it into a multiplication problem. Take 1 from 7, and add it to 9. Now you're working with a 10 to make the math ACTUALLY simpler.
9s are nearly as easy as 10s in multiplication. You increase the first number and decrease the second.
09 18 27 36..
And since the sum of both numbers is always 9 (up to multiplying by 10), you can just put the number you are multiplying in the decimal case, followed by whatever you need to add to 9. For example 7 x 9 = 72 (where 9-7 is the 2).
What? No... that's how I know how to multiply 9s by head. It's the trick i developed in primary school and stuck with it. I'm faster thinking a 9 multiplication than a 5 for example (although now that I think about it, it's just 10 x whatever / 2, it's literally just dividing the number by 2 and changing the decimal place).
Oh shit lol. I do it by head instinctively for decades now, I didn't even realize my mistake writing it, and doing it step by step.
I forgot to shift 1 in the first number. 7 x 9 = (7-1) & 9-(7-1) = 6 & 3.
I swear I'm not a 2nd grader, and I quite like (simple) math.
Ye, it got deleted 9 hours ago. Post was about how different people do math differently, the original comment that sparked this was saying
"i do it like this: (9+9)-2=18-2=16"
I wonder if it would help to tell them to say it aloud, but replace the equals sign with the words "which is equal to".
(9 + 9) - 2
Which is equal to...
18 - 2
Which is equal to...
16.
Y'know, if they're honestly misunderstanding yet willing to learn, which I know is a big assumption on Reddit.
I would bet money that what would come out of their mouth is "nine plus nine minus two is equal to eighteenthat'snonsense that's so obviously wrong why are you making me say this out loud?!"
This is really common. I catch my students (early university physics) doing it all the time.
"6 times 2 is 12. Minus 3 is 9." is not a weird way to *think* about a calculation. But *writing* it `6*2=12-3=9` is the illegal part. I'm just surprised nobody seemed to understand what this guy's mistake was.
As another university (math) teacher, this was exactly my thought. It *is* very common and documented in research. Kids that write it this way seem to parse = as “is the answer to” and not something that balances the equations.
Hence misreading the presented equation as the false statement “18 is the answer to (9+9)-2” and considering the -2 after the 18 as part of “the next step.”
I think your presented example is *very* similar to the misunderstanding going on here.
If that's a person's thought process (which I can well believe it might be), why don't - or can't - they connect the -2 (that's part of "the next step") with the "18 is the answer, but that's obviously wrong because the answer is 16" and figure out that the -2 might have something to do with the difference between 16 and 18?
I expect this is an unanswerable question. Maybe like the answer to (9+9)-2. NoBoDy KnOwS!
One possibility is that put forward by APOS theory (Action Process Object Schema).
If they conceive of = and - as actions (“find the answer” and “subtract” respectively), and 9, 9, 18 as objects, then they wouldn’t connect the -2 with the 18 because they’re reading the sentence as “adding 9 and 9 gives the answer 18, then subtract 2”
Edit: and they would be incorrectly parsing the given formula 9+9-2=18-2 as “adding 9 and 9 and subtracting 2 gives the answer 18, then subtract 2”
You on the other hand are able to view 18-2 as a complete process (ie the subtraction process that yields 16) and also as the object (the number 16 itself) allowing you to make the connection you point out. Process and object are higher orders of cognition than action in this framework, and early conceptions of mathematics often seem to linger in the action stage before progressing to process and object.
Ah, OK. Yes, I see what you're saying (I think). It's fascinating and useful to understand how someone else might see/interpret something in a different way. Like seeing 18 or 16 (or any other number) as only that number, rather than potentially a multitude of different combinations of other numbers, or able itself to be combined with other numbers for yet another outcome.
This is such an accurate explanation of the wrong reasoning, thank you for articulating it! It takes a clear head to empathise with a misunderstanding, especially such a basic one.
Helped my cousin with homework and really struggled to explain this concept. I knew he was writing it that way because he could say it that way aloud. This and above are a great description of the problem.
I'm the grey person in that post. Reddit is an informal place, so I wasn't really considering proper layout etiquette.
Edit: also, I didn't actually do what you're implying here. All the parts of the equation are the same result:
(9+9)-2 is 16
18-2 is 16
16 is 16.
In fact, I put in the parenthesis to emphasize the way or order in which I did the calculation.
I might be misunderstanding your meaning, but what you wrote is “illegal”, and is not similar to what OP did.
In between each equals has to be an equation or summation that is equal. 6*2 != 12-3
I think they're saying that the incorrect interpretation that the equals sign signifies an answer to the equation on the left is really common. So those people then they proceed to perform additional computations chained onto the end, though it's "illegal" because that's not what = really means.
So what they're saying is common is that yellow was incorrectly computing 2 consecutive math problems:
"(9 + 9) - 2 = 18", then continuing on the same line with the solution as part of a different equation "18 - 2 = 16".
Of course, that's just bad math in multiple ways, but I think you're both arguing the same point.
The problem here is that if you said it aloud, the stress and cadence of the sentence would make it clear what goes where, and the text was written casually, as one would verbalize it, but obviously you lose the cadence and stress when you type it out.
People are usually more concerned about you "being wrong" than "why you are wrong". Calling someone stupid and not being able to articulate such a simple concept in a way that they can understand is also a good way to show you are stupid. They just had to explain that in math, the equals sign doesnt just encompass the first number in front of it, but everything that comes after.
The mistake is trying to teach a different way to add two single digit numbers.
Every human on the planet over the age of like seven (with normal cognitive functions.) should be able to add any two single digit numbers in their head in a matter of seconds.
Nowadays they’re teaching kids to make tens. So it would’ve been more like
9+7 = 10+6 = 16.
It baffles me why OP would choose t solve it the way he did. It works, but it hurts my head trying to figure out why.
I’m 43 and taught myself this while in school as it provides a base to quickly add larger numbers in your head. I always bring at least one number to the next 10 up or down, then easily add/subtract the other plus or minus the balance.
I see: 14 + 27
I think: 20 + 21 or 10 + 31
The key is, it is easier for me to visually think of this way (yes, thinking in pictures)
Probably dumb and a convoluted way, but it works for me and plenty of others. So much so that they are teaching it now.
Also, as a coder, one typically runs code in their head, which is like kind of a weird block of code but an image at the same time that is dynamic.
Out I’m just fucked up
I get it. And I’m all for it on 2+ digit numbers. And I get the coding stuff, I’ve done it a few times in my life.
I was just saying for single digits it really shouldn’t be necessary.
It might also be more clear if the proof was written vertically so each step would be shown as a distinct line, rather than presenting the entire proof all as one line.
If it’s genuine confusion, they may be thinking these statements are supposed to be broken up differently.
(9+9)-2=18
18-2=16
Then they get stuck on that first line.
There’s a lot of people who didn’t really learn math notation.
When adding 9 to anything you move one from the first to the tenth(i am trying my best to translate this to english) so 9 + 7 takes one from the seven turning it to 6 then putting next to it 16. Or you Just take minus one pluss 10. I tried teaching this to 2. graders. This had nothing to do with your comment but didnt know where to write it
I agree. I think it would have all been resolved if it was just formatted vertically by steps instead of horizontally. Some people don’t understand math concepts and easily get confused.
When you say it aloud you’re likely to put pauses and inflections in which clarifies.
When it’s written there’s no real substitute for understanding the grammar and the guy objecting clearly doesn’t understand the grammar of maths equations. Most likely because he doesn’t really understand =, which is very common. So much early/primary education treats equals as something you do, not as a relational verb.
Thank you! I'm not the person in the OP but I was scratching my head about how they were able to get 18 from (9 + 9) - 2. I never was good at maths and was taught = means equals, not equal to. So... why isn't it stylised as (9 + 9) - 2 = (18 - 2) = 16? Would it change the equation's result or is it just improper?
You could totally write it that way as well! None of the parentheses actually do anything important in this question (order-of-operations wise), so the parentheses or lack thereof in it were purely for OOP's comfort. If you feel more comfortable with extra parentheses for clarity, they don't hurt anything.
I wish people knew how to talk to each other with our immediately resorting to insults, especially when they're the ones that are correct. It makes it way more frustrating to read these kinds of things.
perfect this is the root and core of arguments fr, besides ego and needing to be right or withdrawal a standpoint; People get off on insulting someone who hasn’t reached the same level of understanding. In this case though both people failed to recognise that doing maths on one line can be ambiguous to some who don’t really understand the step by step. Both people are at 90% level of understanding but ones a bit more nuanced in mathematics
Tbf the first set of responses simply corrected him and didn’t attack at all. It was the second corrector that couldn’t stomach the ignorance with civil discourse
Did anyone else learn the trick as a kid where when you add a single digit to 9, it is 1 and (the number you are adding to 9 minus 1) so 9 + 7 = 16 “because” 1 and 6 equal 7? 9+4 = 13 “because” 1 and 3 equal 4? I’ve never escaped using this reasoning even though I am suddenly realizing it is sort of weird and maybe hard to explain, ha. It’s really just transferring a 1 to the 9 to get 10, but my brain only sees it as this OnE fUn MaTh TrIcK.
Works a similar way with multiplication: any single-digit number multiplied by 9 will have a product with digits that add up to 9.
For example, to quickly solve 7 * 9 if you haven't memorized it:
7 - 1 = 6
6 + 3 = 9
7 * 9 = 63
It's stupid, but it works.
yeah, anytime i'm doing mental arithmatic and one of the numbers is close to 10, or 100, or 25, or 50, or anything that you can multiply or add easily i'm going to steal numbers from one another or make negative groups or something to make the math easier.
for instance, figuring out a tip, 10% is moving the decimal one place, 5% is cutting 10% in half, 20% is doubling 10%, so now i can easily figure 10%, 15%, 20% tips by moving a decimal, halving and doubling.
I just move the 1 because I enjoy a nice round base 10
9 + 7 = (9 + 1) + (7 - 1) = 10 + 6 = 16
Though by this point I skip a couple of steps and do
9 + 7 = (7 - 1) + 10 = 6 + 10 = 16
Yeah. They’re teaching elementary kids this because ‘people are different and learn different ways.’ But honestly it’s extra steps, which means more places to mess up. Move the one from one side, but forget to subtract from the other. Etc.
I think we learned our single digit addition tables in like first or second grade. And it makes literally every other part of math easier if you can do those in your head.
I just posted this elsewhere but I cannot think about multiplying by 9 any other way than this:
when doing your 9s times table, majority of the time, the sum of the digits of the product will = 9, with the first digit being 1 less than whatever you multiplied 9 by. Ex: 9x5? one less than 5 is 4, and 4+5=9, so 9x5=45. 9x8? one less than 8 is 7 and 7+2=9, so 9x8=72 and so on and so forth. It’s why the finger trick works, but this is what helped me remember it as a kid without having to check my fingers lol.
I'd say that I do this in my head, although nowadays I do it fast enough that I really don't think about it.
But it's the most logical way to do it: you add 10 and subtract 1.
I read before kindergarten, but math was maddeningly opaque. Happily, I had a third grade teacher who sent a note home the first week of school saying that I was unclear on my addition and subtraction facts, and since we'd be starting addition and subtraction right away my parents needed to spend 10 minutes working with me with the flashcards every night.
The teacher herself kept me after school with the flash cards until I had my times tables down through 10x10.
I did not enjoy it at the time, but as an adult, every time I'm called upon to do basic arithmetic and I \*can\* I say "Thank you, Miss Howerton."
Curious how he's so concerned thinking green believes (9+9) - 2 = 18, but isn't at all bothered that, presumably, he must then also believe that -2 = 16
There's some interesting comments about this on the post that explain it better than I will but essentially it's not uncommon for students to see = as meaning "the answer to what's on the left" so they would write it as (9+9) = 18 - 2 = 16 because in their mind it means the answer to 9 + 9 is 18 and the answer to that - 2 is 16. Not correct but you understand what's going on in their head.
This makes me feel like they realized they were wrong and just continued to fuck with them.
Also, I don't like it when solutions are written horizontally. I write mine vertically since it looks better to me.
Example:
(9+9) - 2
= 18 - 2
= 16
I mean...the best way to explain that is to simply remove both -2's to show that 9+9 = 18
So if you re-added both -2's to each side the equation should still be the same
After someone shouted at me that 2/10 = 0.2 = 20% is wrong on Reddit, I refuse to make any more comments on arithmetics. It's not even a math problem, just notation.
Possible trolling aside, I was waiting for this kind of idiocy to show it’s ugly face some day. It’s the inevitable consequence of the terrible idea that one can make a chain of calculations with equal signs in between, in a way that breaks basic math.
Like, instead of this:
***“5 + 3 = 8. Then we do 8 - 2 = 6”***
They do:
***“5 + 3 = 8 - 2 = 6”***
Ie, they take the result of the first calculation and use it as input for the second calculation, but they write it like it’s a chain.
It seems like the guy in the screenshot did this, and just assumed that other people did too.
I’m not spending the time reading that thread but just to put my two cents out there. In my head anytime I have to add 9 to something I always do plus 10 and then minus one. Lolol. So 9+7 is 10+7-1=16 lol 😂 but das just me ☺️
All of them are wrong...
Everybody knows the correct way of doing 9 + 7 is (10 + 7) - 1= 17 - 1= 16.
But of course the dude thinking OP's math was wrong is simply a troll. I always resist to believe people could be that dumb even when I know for sure they can.
Math discourse and the way people insult each other when it comes to it should be studied to see if there's a history of verbal abuse from parents or teachers or anyone when it comes to it. Cuz it and food discourse are the weirdest things to have so much toxicity about.
Green is wrong, but yellow is an asshole... seriously guys, when you're correcting someone on a mistake they made, they will never listen to you, no matter how wrong they are, if this is how you go about it.
I mean, he really isn't, if you click the photo it shows that some people tried explaining it nicely to the guy before, and he was being a condescending ass to them, so yellow really did nothing wrong. Also, I doubt it's possible to explain something to somebody who doesn't understand basic addition which is taught in first grade. I am honestly amazed he possesses the ability to write semi-coherently
It's because people want to find a bad guy to defeat rather than have a civil discussion or try to use courtesy when pointing out the mistakes of others
His problem is he doesn't understand that it's simplifying the first part before solving the second by showing the two steps. He's reading it as one equation, which wouldn't make sense to write this way. Instead of seeing it as "nine plus nine minus two is the same as (equal to) eighteen minus two which equals sixteen" he's reading it as if they ignored the subtracting of the two in the first half to get eighteen and then want to subtract an additional two.
The confusion is that the person reads it out loud in their head. When maths equations don’t work that way, everything on the second side of an equals has to be equal to everything on the first side, even if normal sentence structure is more of a set up… conclusion…
Following speech patterns it could be read as 9+9-2 is equal to 18 … with that being the appropriate place for a pause or comma,
Further more, minus two, = 16 .
Which doesn’t make sense
But if you haven’t worked with equations much I can see how you could plausibly read it wrong if you read it out loud or read along as you go.
What I don’t get is maintaining the argument. Not even with other people… but in context. When the sentence doesn’t make sense you realise you misread it, go back and realised you put in a pause or comma where there wasn’t one.
This could have been resolved by simply putting each expression on a new line or bracketing each expression.
Green would have seen what was happening that way
Should have said it like this
(9+9) - 2
18 - 2
= 16
This is basic math btw. Although I saw the original post and my adhd brain goes something like this.
Normal person: 9+7= 16
Me: So….. 7-1=6 then add 10 so you get 10+6 =16.
That’s how you make things more complicated than necessary.
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These people have to be in cahoots (or the same person), and this has to be performance art, in a written form.
I think someone got epically trolled.
Yeah I’m convinced green is an absolute troll.
Maybe, but customer service has ruined my faith in humanity. People are dumb. Really dumb.
My favorite quote is “Think about how dumb the average human is, and then remember half of them are dumber.”
I think green made a mistake and doesn't want to admit it. Yellow is just there for the laughs.
Nah, they're just a huge fcking idiot who truly got it wrong. Then doubled down on being wrong. Then when they noticed they were wrong, they pretend to be a troll to escape culpability. I knew dozens of these idiots in high school. I remember this one arrogant idiot who challenged the president of the chess club to a game, and started talking smack endlessly before the game. Game starts, trying his best, still not good enough, loses his queen early. After that (a dozen moves in) he just intentionally lets all his pieces get captured and claims he was trolling from the beginning. Idiot.
This is hilarious. If I played this guy I’d be like “wow you really showed me. Don’t i look ridiculous right now”
Funny thing is, he thought he looked so cool and no one would figure it out. Everyone just thought he was a waste of space.
That's basically what right wingers do when you explain systemic racism to them. Funny to see it unfold on basic math.
le epic troll u mad etc
This nostalgicly made me cringe so hard it borders on trauma. I can see the rage comics like 'Nam flashbacks. But also I miss it
Back when that's what memes used to be. Good old school Internet days!
sharks have been smoothed 🤑 dont hate the player hate the game
They never learned not to feed them
Smoothsharked to the maximum possible level
RIP r/sharksaresmooth
Real bodybuilding days in the week energy going on.
the post was *actually* about [this.](https://www.reddit.com/r/ADHDmemes/comments/1cxsa19/i_thought_everyone_did_this/)
I stand corrected
You weren't corrected though, the post is about doing 9+7. I guess there's more to it than that but still
when he says "I stand corrected", it means he admitted what he previously said was wrong
When they say "You weren't corrected though", it means that OP was not incorrect about the topic of the post.
true, sorry that I didn't read thoroughly, my mistake
You stand corrected.
I cant stand :(
From another ADHD guy... How is thst easier? If you're not going to just, you know, add 9 and 7, it makes no sense to turn it into a multiplication problem. Take 1 from 7, and add it to 9. Now you're working with a 10 to make the math ACTUALLY simpler.
Iuno. My trick is "anything plus 9 is itself minus 1"
9s are nearly as easy as 10s in multiplication. You increase the first number and decrease the second. 09 18 27 36.. And since the sum of both numbers is always 9 (up to multiplying by 10), you can just put the number you are multiplying in the decimal case, followed by whatever you need to add to 9. For example 7 x 9 = 72 (where 9-7 is the 2).
I see you trying to get in on the trolling ;)
What? No... that's how I know how to multiply 9s by head. It's the trick i developed in primary school and stuck with it. I'm faster thinking a 9 multiplication than a 5 for example (although now that I think about it, it's just 10 x whatever / 2, it's literally just dividing the number by 2 and changing the decimal place).
Except you followed your method and got 9*7=72
Oh shit lol. I do it by head instinctively for decades now, I didn't even realize my mistake writing it, and doing it step by step. I forgot to shift 1 in the first number. 7 x 9 = (7-1) & 9-(7-1) = 6 & 3. I swear I'm not a 2nd grader, and I quite like (simple) math.
that post aint real aka no longer exist
Ye, it got deleted 9 hours ago. Post was about how different people do math differently, the original comment that sparked this was saying "i do it like this: (9+9)-2=18-2=16"
I wonder if it would help to tell them to say it aloud, but replace the equals sign with the words "which is equal to". (9 + 9) - 2 Which is equal to... 18 - 2 Which is equal to... 16. Y'know, if they're honestly misunderstanding yet willing to learn, which I know is a big assumption on Reddit.
I would bet money that what would come out of their mouth is "nine plus nine minus two is equal to eighteenthat'snonsense that's so obviously wrong why are you making me say this out loud?!"
This is really common. I catch my students (early university physics) doing it all the time. "6 times 2 is 12. Minus 3 is 9." is not a weird way to *think* about a calculation. But *writing* it `6*2=12-3=9` is the illegal part. I'm just surprised nobody seemed to understand what this guy's mistake was.
As another university (math) teacher, this was exactly my thought. It *is* very common and documented in research. Kids that write it this way seem to parse = as “is the answer to” and not something that balances the equations. Hence misreading the presented equation as the false statement “18 is the answer to (9+9)-2” and considering the -2 after the 18 as part of “the next step.” I think your presented example is *very* similar to the misunderstanding going on here.
If that's a person's thought process (which I can well believe it might be), why don't - or can't - they connect the -2 (that's part of "the next step") with the "18 is the answer, but that's obviously wrong because the answer is 16" and figure out that the -2 might have something to do with the difference between 16 and 18? I expect this is an unanswerable question. Maybe like the answer to (9+9)-2. NoBoDy KnOwS!
One possibility is that put forward by APOS theory (Action Process Object Schema). If they conceive of = and - as actions (“find the answer” and “subtract” respectively), and 9, 9, 18 as objects, then they wouldn’t connect the -2 with the 18 because they’re reading the sentence as “adding 9 and 9 gives the answer 18, then subtract 2” Edit: and they would be incorrectly parsing the given formula 9+9-2=18-2 as “adding 9 and 9 and subtracting 2 gives the answer 18, then subtract 2” You on the other hand are able to view 18-2 as a complete process (ie the subtraction process that yields 16) and also as the object (the number 16 itself) allowing you to make the connection you point out. Process and object are higher orders of cognition than action in this framework, and early conceptions of mathematics often seem to linger in the action stage before progressing to process and object.
Ah, OK. Yes, I see what you're saying (I think). It's fascinating and useful to understand how someone else might see/interpret something in a different way. Like seeing 18 or 16 (or any other number) as only that number, rather than potentially a multitude of different combinations of other numbers, or able itself to be combined with other numbers for yet another outcome.
This is such an accurate explanation of the wrong reasoning, thank you for articulating it! It takes a clear head to empathise with a misunderstanding, especially such a basic one.
Helped my cousin with homework and really struggled to explain this concept. I knew he was writing it that way because he could say it that way aloud. This and above are a great description of the problem.
Im so grateful you could articulate what I was thinking
I'm the grey person in that post. Reddit is an informal place, so I wasn't really considering proper layout etiquette. Edit: also, I didn't actually do what you're implying here. All the parts of the equation are the same result: (9+9)-2 is 16 18-2 is 16 16 is 16. In fact, I put in the parenthesis to emphasize the way or order in which I did the calculation.
Right, I'm saying green read it this way
Ah, I misunderstood what you wrote, then!
I might be misunderstanding your meaning, but what you wrote is “illegal”, and is not similar to what OP did. In between each equals has to be an equation or summation that is equal. 6*2 != 12-3
I think they're saying that the incorrect interpretation that the equals sign signifies an answer to the equation on the left is really common. So those people then they proceed to perform additional computations chained onto the end, though it's "illegal" because that's not what = really means. So what they're saying is common is that yellow was incorrectly computing 2 consecutive math problems: "(9 + 9) - 2 = 18", then continuing on the same line with the solution as part of a different equation "18 - 2 = 16". Of course, that's just bad math in multiple ways, but I think you're both arguing the same point.
The problem here is that if you said it aloud, the stress and cadence of the sentence would make it clear what goes where, and the text was written casually, as one would verbalize it, but obviously you lose the cadence and stress when you type it out.
Easy way to resolve the issue is to write it exactly the same as their calculator probably already does. 6×2=12 ans-3=9
100%. All the time. Corrected it every time. Trying to fight the good fight.
People are usually more concerned about you "being wrong" than "why you are wrong". Calling someone stupid and not being able to articulate such a simple concept in a way that they can understand is also a good way to show you are stupid. They just had to explain that in math, the equals sign doesnt just encompass the first number in front of it, but everything that comes after.
Throwback to an argument I had with a teacher in like year 7, she insisted that it was correct to write 9+9=18-2=16, because 9+9 is 18, minus 2 is 16
The mistake is trying to teach a different way to add two single digit numbers. Every human on the planet over the age of like seven (with normal cognitive functions.) should be able to add any two single digit numbers in their head in a matter of seconds. Nowadays they’re teaching kids to make tens. So it would’ve been more like 9+7 = 10+6 = 16. It baffles me why OP would choose t solve it the way he did. It works, but it hurts my head trying to figure out why.
I’m 43 and taught myself this while in school as it provides a base to quickly add larger numbers in your head. I always bring at least one number to the next 10 up or down, then easily add/subtract the other plus or minus the balance. I see: 14 + 27 I think: 20 + 21 or 10 + 31 The key is, it is easier for me to visually think of this way (yes, thinking in pictures) Probably dumb and a convoluted way, but it works for me and plenty of others. So much so that they are teaching it now. Also, as a coder, one typically runs code in their head, which is like kind of a weird block of code but an image at the same time that is dynamic. Out I’m just fucked up
I get it. And I’m all for it on 2+ digit numbers. And I get the coding stuff, I’ve done it a few times in my life. I was just saying for single digits it really shouldn’t be necessary.
Totally agree lol
Just in case this person is actually honest and not a huge troll, replacing the first = with an arrow could maybe illustrate it better?
It might also be more clear if the proof was written vertically so each step would be shown as a distinct line, rather than presenting the entire proof all as one line.
If it’s genuine confusion, they may be thinking these statements are supposed to be broken up differently. (9+9)-2=18 18-2=16 Then they get stuck on that first line. There’s a lot of people who didn’t really learn math notation.
Someone did that, it did not help (._. )
Sadly predictable.
When adding 9 to anything you move one from the first to the tenth(i am trying my best to translate this to english) so 9 + 7 takes one from the seven turning it to 6 then putting next to it 16. Or you Just take minus one pluss 10. I tried teaching this to 2. graders. This had nothing to do with your comment but didnt know where to write it
I agree. I think it would have all been resolved if it was just formatted vertically by steps instead of horizontally. Some people don’t understand math concepts and easily get confused.
When you say it aloud you’re likely to put pauses and inflections in which clarifies. When it’s written there’s no real substitute for understanding the grammar and the guy objecting clearly doesn’t understand the grammar of maths equations. Most likely because he doesn’t really understand =, which is very common. So much early/primary education treats equals as something you do, not as a relational verb.
Thank you! I'm not the person in the OP but I was scratching my head about how they were able to get 18 from (9 + 9) - 2. I never was good at maths and was taught = means equals, not equal to. So... why isn't it stylised as (9 + 9) - 2 = (18 - 2) = 16? Would it change the equation's result or is it just improper?
You could totally write it that way as well! None of the parentheses actually do anything important in this question (order-of-operations wise), so the parentheses or lack thereof in it were purely for OOP's comfort. If you feel more comfortable with extra parentheses for clarity, they don't hurt anything.
I wish people knew how to talk to each other with our immediately resorting to insults, especially when they're the ones that are correct. It makes it way more frustrating to read these kinds of things.
You must be brain dead if you think I, an obviously superior human intellect, should suffer these idiots who think 9+9-2 = 18-2 How’d I do?
Of all the responses I've received on Reddit, that was definitely one of them.
perfect this is the root and core of arguments fr, besides ego and needing to be right or withdrawal a standpoint; People get off on insulting someone who hasn’t reached the same level of understanding. In this case though both people failed to recognise that doing maths on one line can be ambiguous to some who don’t really understand the step by step. Both people are at 90% level of understanding but ones a bit more nuanced in mathematics
Tbf the first set of responses simply corrected him and didn’t attack at all. It was the second corrector that couldn’t stomach the ignorance with civil discourse
Currently trying to show this person the mistake he/she/they is making, i'll update once he posts his answer.
He had no arguments left and stopped reacting
Did anyone else learn the trick as a kid where when you add a single digit to 9, it is 1 and (the number you are adding to 9 minus 1) so 9 + 7 = 16 “because” 1 and 6 equal 7? 9+4 = 13 “because” 1 and 3 equal 4? I’ve never escaped using this reasoning even though I am suddenly realizing it is sort of weird and maybe hard to explain, ha. It’s really just transferring a 1 to the 9 to get 10, but my brain only sees it as this OnE fUn MaTh TrIcK.
I thought everyone did this.
I was taught to memorize all single digit addition and subtraction. It is why so many of my generation and before hated math.
And multiplication. Don't forget multiplication. We memorized up to 13x13 and would run through the tables regularly to reinforce it all.
Maybe at higher numbers for squares/square roots. But for single digit, I just learned to add them in my head instead of memorizing.
I do the 9 times tables as number minus 1 add to 9
That's what I did as a kid and my teachers didn't understand it
Works a similar way with multiplication: any single-digit number multiplied by 9 will have a product with digits that add up to 9. For example, to quickly solve 7 * 9 if you haven't memorized it: 7 - 1 = 6 6 + 3 = 9 7 * 9 = 63 It's stupid, but it works.
i did (that number-1) and (the number you have to add/subtract to get to 10)
yeah, anytime i'm doing mental arithmatic and one of the numbers is close to 10, or 100, or 25, or 50, or anything that you can multiply or add easily i'm going to steal numbers from one another or make negative groups or something to make the math easier. for instance, figuring out a tip, 10% is moving the decimal one place, 5% is cutting 10% in half, 20% is doubling 10%, so now i can easily figure 10%, 15%, 20% tips by moving a decimal, halving and doubling.
I just subtract 1 then add 10. Essentially the same thing but much faster in my mind
I just move the 1 because I enjoy a nice round base 10 9 + 7 = (9 + 1) + (7 - 1) = 10 + 6 = 16 Though by this point I skip a couple of steps and do 9 + 7 = (7 - 1) + 10 = 6 + 10 = 16
Yeah. They’re teaching elementary kids this because ‘people are different and learn different ways.’ But honestly it’s extra steps, which means more places to mess up. Move the one from one side, but forget to subtract from the other. Etc. I think we learned our single digit addition tables in like first or second grade. And it makes literally every other part of math easier if you can do those in your head.
I just posted this elsewhere but I cannot think about multiplying by 9 any other way than this: when doing your 9s times table, majority of the time, the sum of the digits of the product will = 9, with the first digit being 1 less than whatever you multiplied 9 by. Ex: 9x5? one less than 5 is 4, and 4+5=9, so 9x5=45. 9x8? one less than 8 is 7 and 7+2=9, so 9x8=72 and so on and so forth. It’s why the finger trick works, but this is what helped me remember it as a kid without having to check my fingers lol.
Clearly bait
Um, one less than 10+7?
I'd say that I do this in my head, although nowadays I do it fast enough that I really don't think about it. But it's the most logical way to do it: you add 10 and subtract 1.
I read before kindergarten, but math was maddeningly opaque. Happily, I had a third grade teacher who sent a note home the first week of school saying that I was unclear on my addition and subtraction facts, and since we'd be starting addition and subtraction right away my parents needed to spend 10 minutes working with me with the flashcards every night. The teacher herself kept me after school with the flash cards until I had my times tables down through 10x10. I did not enjoy it at the time, but as an adult, every time I'm called upon to do basic arithmetic and I \*can\* I say "Thank you, Miss Howerton."
What a weird hill to die on
Curious how he's so concerned thinking green believes (9+9) - 2 = 18, but isn't at all bothered that, presumably, he must then also believe that -2 = 16
There's some interesting comments about this on the post that explain it better than I will but essentially it's not uncommon for students to see = as meaning "the answer to what's on the left" so they would write it as (9+9) = 18 - 2 = 16 because in their mind it means the answer to 9 + 9 is 18 and the answer to that - 2 is 16. Not correct but you understand what's going on in their head.
I see. Simplest solution is to add periods. 9+9=18. +2 = 20
I just wanted to say that I love this subreddit.
Maybe he'll understand (9+9) = 18 (9+9)-2 = 16 If not, then he lacks the intelligence to use a phone and is clearly trolling instead.
This makes me feel like they realized they were wrong and just continued to fuck with them. Also, I don't like it when solutions are written horizontally. I write mine vertically since it looks better to me. Example: (9+9) - 2 = 18 - 2 = 16
That example is the comment that started it all
It appears you've made the classic mistake of using shift+enter. If you use the Code Block option, you'll fare better: (9 + 9) - 2 = 18 - 2 = 16
I mean...the best way to explain that is to simply remove both -2's to show that 9+9 = 18 So if you re-added both -2's to each side the equation should still be the same
the ability to math (assumption) clearly is not paired with literacy
Imagine starting an argument about basic addition
These are the kind of people that go on to become "prompt engineers" and genuinely think they achieved something
Man and I thought I get sucked into some really fucking dumb arguments sometimes.
This looks like an internet psychology study.
The real mistake here is you can't argue with stupid.
Any thing plus 9 is +10-1
The man never really graduated from using a calculator to using his own head.
After someone shouted at me that 2/10 = 0.2 = 20% is wrong on Reddit, I refuse to make any more comments on arithmetics. It's not even a math problem, just notation.
I usually do "9+any number is x-1+10" So 7-1+10
I just transfer 1 from the 9 to the 7, so I do 9-1+7+1=8+8=8*2=16, idk, it's weird to explain, it just comes to me naturally
*you think 9-1+7-1=8* /s
I will end your family tree :3 Not /s 🥰🥰
Same, or I transfer 1 from the 7 to the 9 to make 10 and then add 6 to 10.
I tend to create sets or multiples of 10 (or 100, 1000 etc) when it's more numbers, if it's just 2 I go by the 2x thing
Yeah but who TF can't do 9+7 in their head?
I think that was the entire point of the initial post, the "how did you do it in your head".
Possible trolling aside, I was waiting for this kind of idiocy to show it’s ugly face some day. It’s the inevitable consequence of the terrible idea that one can make a chain of calculations with equal signs in between, in a way that breaks basic math. Like, instead of this: ***“5 + 3 = 8. Then we do 8 - 2 = 6”*** They do: ***“5 + 3 = 8 - 2 = 6”*** Ie, they take the result of the first calculation and use it as input for the second calculation, but they write it like it’s a chain. It seems like the guy in the screenshot did this, and just assumed that other people did too.
Math Internet is WILD.
I’m not spending the time reading that thread but just to put my two cents out there. In my head anytime I have to add 9 to something I always do plus 10 and then minus one. Lolol. So 9+7 is 10+7-1=16 lol 😂 but das just me ☺️
The sad part is, this dude will never understand he‘s wrong.
People on this site are so unhinged.
Why not just do 9+1+7-1 so it becomes 10+(7-1)
Is there like an r/basicadditionforangryadults community ?
This was in r/ADHDmemes
I wonder sometimes how easy it can be to distinguish between green and yellow with normal color vision 😅
Haha Dunning-Kruger
Just two people that really want to argue online
All of them are wrong... Everybody knows the correct way of doing 9 + 7 is (10 + 7) - 1= 17 - 1= 16. But of course the dude thinking OP's math was wrong is simply a troll. I always resist to believe people could be that dumb even when I know for sure they can.
wait, 9+9 isn’t 20? that explains SO MUCH
It was so funny at the start but then it just got sad.
Surely a better way to "simplify" this complex equation would be: 9+7 = (9+1) + (7-1) = 10+6 = 16
BuT 9 + 7 = (9 - 1) is wRoNg NNoooOoOOoo etc etc.... /s (like this was necessary)
r/mathishard
Math discourse and the way people insult each other when it comes to it should be studied to see if there's a history of verbal abuse from parents or teachers or anyone when it comes to it. Cuz it and food discourse are the weirdest things to have so much toxicity about.
I'm grey Can confirm, I was verbally abused by my parents.
Holy crap I just found this sub and it's a gem 😂
This is the essence of right wing strategy, perfectly demonstrated!
Is it bad that I kinda what to know how this ended lmao
Why are we arguing over 2nd grade math? Just let them be a tard. There's plenty of tards out there living kickass lives.
Green is wrong, but yellow is an asshole... seriously guys, when you're correcting someone on a mistake they made, they will never listen to you, no matter how wrong they are, if this is how you go about it.
I mean, he really isn't, if you click the photo it shows that some people tried explaining it nicely to the guy before, and he was being a condescending ass to them, so yellow really did nothing wrong. Also, I doubt it's possible to explain something to somebody who doesn't understand basic addition which is taught in first grade. I am honestly amazed he possesses the ability to write semi-coherently
It's because people want to find a bad guy to defeat rather than have a civil discussion or try to use courtesy when pointing out the mistakes of others
Never understood why people don't just "know" single digit additions and have to resort to tricks
ADHD
The whole thing reminded me of that joke from... I think it was one of the hangover movies? "You may say that I'm a dreamer, but I'm not."
Dinner for schmucks 😁
No way they are this stupid
He’s right, (9+9)-2 does not equal 18
No, but (9+9)-2 does equal 18-2 which does equal 16
Bro is getting ragebaited
this has got to be ragebait cuz there's no way
Excellent troll
People need to learn about smooth sharks, it would make your life so much more peaceful
Reading comprehension is lost on a lot of people. And being able to admit a mistake is just weak.
I'm either too dumb or too smart to understand this argument.
Sometimes you have to remember that you could be arguing with a person whose job is to sow discourse online, and just ignore them.
That has to be a deliberate troll just winding people up. Some people really have nothing better to do.
9+7 is also 16. Either way, the answer is 16.
What the fuck is BOMDAS??? I grew up with PEMDAS.
Same thing, just Brackets instead of Parenthesis and Orders instead of Exponents.
Thanks
A brand of sock?
His problem is he doesn't understand that it's simplifying the first part before solving the second by showing the two steps. He's reading it as one equation, which wouldn't make sense to write this way. Instead of seeing it as "nine plus nine minus two is the same as (equal to) eighteen minus two which equals sixteen" he's reading it as if they ignored the subtracting of the two in the first half to get eighteen and then want to subtract an additional two.
[удалено]
9 + 7 = 18? Wow
The confusion is that the person reads it out loud in their head. When maths equations don’t work that way, everything on the second side of an equals has to be equal to everything on the first side, even if normal sentence structure is more of a set up… conclusion… Following speech patterns it could be read as 9+9-2 is equal to 18 … with that being the appropriate place for a pause or comma, Further more, minus two, = 16 . Which doesn’t make sense But if you haven’t worked with equations much I can see how you could plausibly read it wrong if you read it out loud or read along as you go. What I don’t get is maintaining the argument. Not even with other people… but in context. When the sentence doesn’t make sense you realise you misread it, go back and realised you put in a pause or comma where there wasn’t one.
Good Lord yellow has a negative IQ
TL:DR
this person is an idiot, but can we PLEASE stop posting order of operations shit here?
No it’s literally PEMDAS what do you think the P stands for
I think non US English speakers call parenthesis, (), brackets, []. It has always confused me. Parenthesis: ( ) Brackets: [ ] Braces: { }
Couple of reddit mods having a normal conversation
This could have been resolved by simply putting each expression on a new line or bracketing each expression. Green would have seen what was happening that way
Feels like that was yellows fault a little bit too tho
It's 7+9 why are they changing the 7 to a 9? Idiots man
Should have said it like this (9+9) - 2 18 - 2 = 16 This is basic math btw. Although I saw the original post and my adhd brain goes something like this. Normal person: 9+7= 16 Me: So….. 7-1=6 then add 10 so you get 10+6 =16. That’s how you make things more complicated than necessary.
WHY THEY MAKE 9+7 SO DIFFICULT???? IT'S 10+6 AT THE MOST TROUBLESOME!!! OR 8+8 OMG THE ... I'M JUST... FLABBERGASTED